DUNEPRISM PRODUCTION UPDATE 2017-11-30 2 BEAMLINE AND ND GEOMETRY - - PowerPoint PPT Presentation

DUNEPRISM PRODUCTION UPDATE

LUKE PICKERING, JAKE CALCUTT

BEAMLINE AND ND GEOMETRY SETUP

▸ Flux simulation fires hadrons along +z. ▸ Needs to be rotated to expose the near detector to the correct neutrino flux. ▸ Rotate beam coordinates by dip angle (5.8 degrees) and then shift beam sim origin to

(0,58.1m,-575m)

Luke Pickering 2017-11-30 2 Beam sim z 5.8o

ND HALL

575m 58.1m TGT

(cm) (cm)

SANITY CHECK OF GENIE EVENTS

Luke Pickering 2017-11-30 3 Neutrino momentum y:x Neutrino momentum y:z Neutrino energy Interaction pos y:x Interaction pos y:z Flux window was too short for the dip angle so the back of the detector was clipped. Re-running this now, but didn’t feel that it needed to delay as it doesn’t really affect any conclusions Beam is definitely heading downward as expected Spectrum looks sensible enough (N.B. averaged over entire off-axis range)

PRODUCTION STATS: PER FILE

Luke Pickering 2017-11-30 4

Stage g4lbnf GENIE (5000) GENIE (10000) RooTracker (10000) edepsim (10000) Total (10000) argon_box.py (5000x2) Time ~2 hours 80m 180m ~10s 20m ~4.75 hours 94m POT 1E+05 1.04E+16 2.09E+16 — — — — Entries 101000 5000 10000 — — — — Neutrinos Used 101000 e.g. 370000 e.g. 750000 — — — — File Size 80 Mb 9.7 Mb 20 Mb 7 Mb 2.4 Gb 2.5 Gb 7.4 Gb

▸ Using a scaled up example of the argon_box.py results from Jake for comparison. ▸ Might be worth moving to edep-sim. ▸ Current aim is to push 20k events through from the start and get that to Guang ASAP (i.e.

Friday Dec 1st).

▸ Can work on intermediate steps while that output is being assessed by Guang.

ARE OUR PRODUCTION GOALS FEASIBLE

▸ Scaling the numbers on the previous slide up: ▸ This simulates at all off-axis positions simultaneously so ‘collect

data’ at NStops times faster.

▸ 4m wide FV for 32m off-axis span we need 8 stops. ▸ Expected yearly POT is 1.4E21 POT ▸ So for 11x 7year POT/8 stops, we need to simulate 13.475E21 POT

• n this 36m box ~= 650,000 files @ 2.1E16 POT per 10k events:

▸ ~3 Million CPU hours ▸ ~1.6 PB of disk space if we save intermediate stages ▸ ~6.5 Trillion events ▸ I think we need to re-assess the production size, can easily scale

predictions to such event rates and force poisson errors on these.

▸ I think 1k files would be a good start — Even at this level cannot

feasibly save G4 output @ 2+ TB. (10 mil events for nu-mode)

Luke Pickering 2017-11-30 5

SANITY CHECK OF PREDICTED EVENT RATES

▸ Possible that I am screwing something up in the geometry

and thus the NEvents <=> POT correspondence is not correct.

▸ Check against event rates that I previously calculated. ▸ Use 5x4x2.5 ‘FV’ as for the ND workshop study ▸ Ask for one cycle’s worth of events at the on axis position ▸ I think this shows good correspondence.

Luke Pickering 2017-11-30 6

Offset νµCCInc NCInc 0 m 5.1 1.5 5 m 3.9 1.2 10 m 1.8 0.53 15 m 0.85 0.24 20 m 0.47 0.13 25 m 0.28 0.081 30 m 0.18 0.053

ND Workshop Running GENIE + Flux driver

A NOTE ON NEUTRINO RE-USE

▸ When throwing actual events in the detector, decay parents are re-used a huge

number of times:

▸ ~100k decay parents used as input (equiv to 1E6 POT). ▸ The problems that Cris saw before were exaggerated because that flux

generation tool forces neutrinos through (XOffset,0,0) in detector coordinates.

▸ My tools here: https://github.com/luketpickering/DUNEPrismTools are built on top

• f those scripts but are hopefully much more configurable and allow you to

specify a flux window (in a same way as the GENIE flux driver).

▸ If there is interest in using/building on these rather than just the scripts that

Laura sent, I will add Cris as a contributor to the repo.

▸ I propose to re-use each decay parent O(10) times but randomly spraying them

• ver the 36m wide ‘detector’ — this should stop the ‘line’ problems that Cris saw

where one high energy neutrino is dragged off axis and leaves a line in the plot.

▸ It does mean that the parents are re-used, I’m not sure we can get around this… ▸ This isn’t implemented in the code, but should be a five minute job. ▸ Ideas, Concerns, Expectations?

Luke Pickering 2017-11-30 7 Ray tracing rejection (flux de-weighting) Interaction rejection (xsec de-weighting)

NEXT STEPS

▸ Running a larger nominal beam simulation sample

today (1k files).

▸ Will get those pulled to MSU so that Cris can start

playing with them.

▸ Build FD Fluxes (and FD/ND flux ratios). ▸ Will run in a few other configurations and determine

OAA vs. ENu reweighting histograms (similar to Tejin’s talk at the DUNE ND meeting 2017-11-30):

▸ Horn shift, Current shift, Water layer thickness ▸ Want to also get PPFX working for hadronisation

parameter reweights.

Luke Pickering 2017-11-30 8

THANK YOU

WE APOLOGISE FOR ANY INCONVENIENCE